The DBMS_OUTLN package, synonymous with OUTLN_PKG, contains the functional interface for subprograms associated with the management of stored outlines.

A stored outline is the stored data that pertains to an execution plan for a given SQL statement. It enables the optimizer to repeatedly re-create execution plans that are equivalent to the plan originally generated along with the outline.The data stored in an outline consists, in part, of a set of hints that are used to achieve plan stability.